/*
 * Copyright (C) 2014 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.camera.ui.focus;

import android.graphics.Canvas;
import android.graphics.Paint;

import com.android.camera.ui.motion.InterpolateUtils;
import com.android.camera.ui.motion.Invalidator;

/**
 * Manual focus ring animation renderer.
 */
class ManualFocusRing extends FocusRingRenderer
{
    /**
     * The manual focus ring encapsulates the animation logic for visualizing
     * a focus event when triggered by a physical screen touch.
     *
     * @param invalidator        the object to invalidate while running.
     * @param ringPaint          the paint to draw the ring with.
     * @param exitDurationMillis the fade out time in milliseconds.
     */
    public ManualFocusRing(Invalidator invalidator, Paint ringPaint,
                           float exitDurationMillis)
    {
        super(invalidator, ringPaint, 0.0f, exitDurationMillis);
    }

    @Override
    public void draw(long t, long dt, Canvas canvas)
    {
        float ringRadius = mRingRadius.update(dt);
        processStates(t);

        if (!isActive())
        {
            return;
        }

        mInvalidator.invalidate();
        int ringAlpha = 255;

        if (mFocusState == FocusState.STATE_FADE_OUT)
        {
            float rFade = InterpolateUtils.unitRatio(t, mExitStartMillis, mExitDurationMillis);
            ringAlpha = (int) InterpolateUtils.lerp(255, 0, mExitOpacityCurve.valueAt(rFade));
        } else if (mFocusState == FocusState.STATE_HARD_STOP)
        {
            float rFade = InterpolateUtils.unitRatio(t, mHardExitStartMillis,
                    mHardExitDurationMillis);
            ringAlpha = (int) InterpolateUtils.lerp(255, 0, mExitOpacityCurve.valueAt(rFade));
        } else if (mFocusState == FocusState.STATE_INACTIVE)
        {
            ringAlpha = 0;
        }

        mRingPaint.setAlpha(ringAlpha);
        canvas.drawCircle(getCenterX(), getCenterY(), ringRadius, mRingPaint);
    }

    private void processStates(long t)
    {
        if (mFocusState == FocusState.STATE_INACTIVE)
        {
            return;
        }

        if (mFocusState == FocusState.STATE_ENTER
                && (t > mEnterStartMillis + mEnterDurationMillis))
        {
            mFocusState = FocusState.STATE_ACTIVE;
        }

        if (mFocusState == FocusState.STATE_ACTIVE && !mRingRadius.isActive())
        {
            mFocusState = FocusState.STATE_FADE_OUT;
            mExitStartMillis = t;
        }

        if (mFocusState == FocusState.STATE_FADE_OUT && t > mExitStartMillis + mExitDurationMillis)
        {
            mFocusState = FocusState.STATE_INACTIVE;
        }

        if (mFocusState == FocusState.STATE_HARD_STOP
                && t > mHardExitStartMillis + mHardExitDurationMillis)
        {
            mFocusState = FocusState.STATE_INACTIVE;
        }
    }
}
